Insect Discovery and Breeding as Tools for Sustainable Solutions to Organic Waste Management

View the project final report

Commodities

• Agronomic: sugarbeets
• Fruits: citrus, grapes
• Nuts: almonds, pistachios, walnuts
• Vegetables: carrots, onions, tomatoes

Practices

• Animal Production: feed formulation, livestock breeding
• Energy: byproduct utilization
• Soil Management: composting, organic matter

California produces over 400 crops, which in turn yield many more “organic waste residues” during downstream processing, such as fruit and vegetable pulp from juice industries. Some of these organic waste residues are used as substrate for mushroom production, compost, or as filler in animal feed. However, large portions end up in landfills and are considered a problem rather than an economic opportunity. As decomposers and herbivores, the diversity of insect species includes groups highly specialized in their ability to thrive on different organic substrates, and some of these substrates resemble waste residues from food processing industries. Crickets, cockroaches, soldier flies, bottle flies, and mealworms represent the most widely referenced species in studies of organic waste conversion. We argue that both insect discovery (testing of more species) and selective breeding are needed to further advance the potential of insects as converters of organic waste materials. We have data clearly suggesting that within a species, individuals show marked range in “adaptation” (measured as growth rate, nutrition uptake and therefore rate of bioconversion) when reared on specific organic waste materials. Such range in adaptation underscores the potential of selective breeding, and the overall project hypothesis is that we will identify and selectively breed specific species with significantly higher adaptation than strains of insects that are currently available commercially.

The stated goals of this project were to demonstrate how insect discovery and selective breeding can increase sustainable solid waste management practices. Specifically, (1) “mining” insect species diversity for new candidate bio-converters, (2) selectively breeding high performance strains, and (3) characterizing the potential for feeding poultry insects reared on different agricultural wastes. A major outcome from this project was increasing insight into which insect species and improved strains should be used for bioconversion, with insights specifically based on the nutritional and physical composition of the resulting insect by-products. In addition, we have been able to provide novel uses for insect derived by-products (fertilizers, immunostimulants, mushroom substrates) that will further make the burgeoning insect bioconversion sector economically viable.

Throughout the duration of this project, we have used the pursuit and cultivation of novel insect bioconverters as an effective means of recruitment for a new crop of incipient scientists. Under our flagship insect bioconversion program, we have expanded our team to include both interns and hired undergraduates. These students (Brian Cheng, Amanda Favilla, Zhijun Lu, Meredith Martin, and Curtis Carlson) not only have gained valuable experience within a scientific setting, both individually and as a team, but have each developed their own derivative projects alongside our main body of work. This has permitted them to gain knowledge spanning th whole scientific experience, including data collection and curation, analysis, and writing. Due to our combined efforts, several papers are expected to be produced from the work done on this project.

1. Identify new species for organic waste residue conversion, with specific focus on rapid development, nutrition, high conversion ratios, easy extraction of insect body mass, and conversion of recalcitrant residues (those high in tannins or phenolics).
2. Determine the composition and feed potential of insect biomass following rearing on different performing diet regimes. 
3. Establish improved lineages using applied evolutionary techniques, with target goals of increased body mass, development time, or fecundity. Improved lineages performance in these traits will exceed that of their initial populations. 
4. Work together with growers, extension specialists, and researchers cooperating in this project to disseminate findings and recommendations through newsletters, and symposia, and publications